Issue



The future for fan filter units


03/01/2007







FFU market expected to grow through 2010

By Robert McIlvaine and Karen Vacura, The McIlvaine Company

A fan filter unit (FFU) consists of a small blower with a matched fan, an optional digital or solid-state speed controller, and a HEPA/ULPA filter, all enclosed in an aluminum or stainless-steel box. The unit maintains specific airflow and is commonly installed directly into cleanroom ceiling grids. Smaller and more portable than traditional airflow systems, with typical sizes of 2 feet x 2 feet or 2 feet x 4 feet, FFUs can be focused in targeted areas. They can be added to existing cleanrooms without major refitting, enabling updates as needs and standards change.

FFUs, favored in semiconductor cleanrooms, are also utilized in flat-panel display (FPD), nanotechnology, high-tech automotive, life sciences, and food industries, as well as in new technologies such as photovoltaic and fuel cell cleanrooms, according to M&W Zander (Stuttgart, Germany), a leading total facility solutions provider. FFUs are also in use in hospitals and laboratories.

Because performance is improved while installed costs are driven lower, the use of FFUs continues to gain market share over centralized systems, says Howard Abramowitz, president of AirCare Automation, Inc. (Austin, TX), a manufacturer of control cards used in the units. The expansion of smaller clean-air spaces, the creation of special areas within ballroom clean spaces, and minienvironments have created more opportunities for FFUs.

Michael O’Halloran, director of technology at CH2MHill, states that FFUs offer many advantages and are designed for a specific situation and low power consumption. Dominant in the semiconductor industrial lithography tool environment, they are commonly installed with a separate fan unit to control temperature.

FFUs are equipped with either standard AC induction motors or electronically commutated (EC) motors, which are special brushless direct current motors that operate from the AC line. EC motors incorporate specialty drive and control electronics that make the FFUs in a cleanroom easier to adjust, monitor and tie together in a network. This allows the units to operate only when needed, thus saving energy.

EC FFU units require a smart-motor fan system, an interface to the fan, network consolidation, and PC software customization for each individual installation. These systems systems have been the gold standard since the Envirco MAC 10 IQ was introduced in 2001, says Abramowitz. At that time, AC systems were unable to match the performance and system integrity of the EC systems and a clear, two-tier system evolved. With the introduction of AC control systems that operate out-of-the-box, “smarts” could be added to AC systems at a nominal cost and thus began the process of closing the gap between the AC and DC solutions.

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Abramowitz points out that smart FFUs provide monitoring feedback so facility managers can quickly address any failings. Without such controls, failures can go undetected for days or longer.

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Nejat Babür, mechanical department manager at CH2MHill, states that DC motors are frequently used due to energy efficiency benefits. A DC motor can use less power, generating less heat than a standard AC motor. Costs vary depending on how complicated the control systems are and whether a separate cooling unit is required.

DC motors maintain proper airflow by modulating speed internally using a control algorithm that checks the motor torque, an important concern in cleanrooms, Babür explains. For instance, in pharmaceuticals, a constant airflow of 90 ft./min. in ISO 5 (or EU Grade A) areas is required. Currently, about 15 percent of pharmaceutical cleanrooms use FFUs. Fan companies are developing specialized fans as they learn specific pharmaceutical requirements for cGMP compliance.

Les Goldsmith, national specialty filtration sales manager for Envirco, explains that the dominating factors in choosing a fan filter unit are energy efficiency and controllability. Envirco, a division of Fedders Engineered Products, offers the MAC 10® Original, a low-energy, low-sound, low-profile FFU; the MAC 10 IQ, a combination of the GE ECM™ motor, a patented baffling system and a forward-curved fan; and the MAC 10 Rx, featuring a stainless-steel housing, for pharmaceutical processing environments.

The cost of Envirco’s Standard AC 2-foot x 4-foot unit is about $600 USD, and about $800 USD for a DC 2-foot x 4-foot unit with an EC motor. Installation cost is the same.

M&W Zander products include the Ultra Filter Fan Unit for applications that do not require individual speed control and central monitoring. The units can be controlled in groups of up to eight units and, for monitoring purposes, a control panel or a beeper is optional. M&W Zander’s Hightec Ultra Filter Fan Unit is equipped with a DC motor and a control and monitoring system linked to a network through an easy-to-install system, allowing individual settings and monitoring. M&W Zander also offers a compact unit, suitable for applications with limited clearance.

Identifying and selecting energy-efficient units in cleanroom applications can bring about savings in energy costs over the lifetimes of the units while maintaining and improving the effectiveness of contamination control. To characterize performance of FFU products, a series of standard laboratory tests has been developed by Lawrence Berkeley National Laboratory to quantify total pressure efficiency and power consumption across a range of operating conditions (CleanRooms, November 2006).

Current and future FFU sales

The growth in sales of FFUs is first and foremost impacted by the growth of the cleanroom industry. Since much of this growth is taking place in Asia, it is not surprising that there will be more purchases of FFUs in Asia in the coming decade than there will be in the rest of the world combined.

Another factor is the increasing popularity of FFUs as opposed to separate fans and filters. Over the years, the percentage of projects incorporating this design will continue to grow. The trend toward minienvironments instead of big cleanrooms also impacts growth.

Forecasts for FFUs have been compiled for each industry in each country. The following charts show the usage for 2000 and 2006 and forecasts for 2010. FFU sales of 80,000 units are forecast for the U.S. in 2010, while world sales will be 500,000 units (see Table 1). The U.S. market dropped between 2000 and 2002 and only recovered partially by 2006. By 2010, it will only have returned to the 2000 level.

Sales for the same period are displayed in constant dollars with the year 2000 as the base price (see Table 2). They are also in standard unit prices and not adjusted for the lower pricing in Asia. Since prices in Asia are less than half those in Europe and the U.S., a tabulation based on actual selling price would reflect a smaller world market.

M&W Zander, Envirco and Huntair are worldwide suppliers of FFU systems. There are a number of regional suppliers in Europe and Asia, resulting in a high world total of FFU suppliers


Robert McIlvaine is president and founder of The McIlvaine Company in Northfield, IL. The company first published Cleanrooms: World Markets in 1984 and has since continued to publish market and technical information for the cleanroom industry. He can be reached at rmcilvaine@mcilvainecompany.com. Karen Vacura is the air filtration market editor for The McIlvaine Company. She can be reached at kvacura@mcilvainecompany.com.

Karen Vacura is the air filtration market editor for The McIlvaine Company. She can be reached at kvacura@mcilvainecompany.com